Project abstract This proposal is focused on establishing the biocompatibility and the anti-microbial properties of protective coatings which are designed to minimize fracture resistance and enhance chemical durability in ceramic veneers. The biocompatibility of ceramics has long been established. Oral biofilm is one of the best described microbial systems, so the mechanism for bacterial adherence and biofilm formation is well known. Bacterial adhesion to a substrate and the initial biofilm composition is related to topography, surface hydrophobicity, and communication between existing microorganisms. The application of protective coatings introduces a different surface composition on the ceramic. Bacteria present in the oral cavity naturally tend to adhere to ceramic materials or to the interface between tooth and restoration, the cervical third of the proximal surface, and along the gingival margin, where they are protected from mechanical action. However, ceramic with protective coatings present potentially different compositions and assessing biocompatibility is essential. There is currently no information on the effect of protective coatings on the bacterial adherence and cellular viability. The overall objective is to evaluate the biocompatibility and bacteria adhesion to protective coatings on ceramic veneers. We will test the central hypothesis that dental coated ceramic veneers are biocompatible and will minimize if not prevent bacterial adhesion on the surface. This unique and translational research project will determine polymicrobial and monomicrobial adhesion to the protective coatings on the ceramic as well as determine their cytotoxicity on cells. We will test the central hypothesis by pursuing the following specific aims: Aim 1: To test the hypothesis that cell viability experiments for coated and uncoated ceramic disks will produce similar biocompatibility results. Aim 2: To test the hypothesis that the coatings will not promote cytotoxicity of ceramic, thereby showing the novel coating's biocompatibility.